New pivotal data for bispecific antibody epcoritamab (DuoBody CD3xCD20) demonstrates high overall and complete responses in patients with hard-to-treat relapsed/refractory follicular lymphoma .- GenMab + AbbVie

The presentation included data from an optimized step-up dosing schedule for FL patients showing a reduction in risk and severity of Grade 2+ cytokine release syndrome (CRS), a common side effect of T-cell engaging cancer treatments. These results were presented at the 2023 65th Annual Meeting and Exposition of the American Society of Hematology (ASH), being held in San Diego, California, December 9-12, 2023 (Abstract #1655).

“Despite treatment advances for patients with follicular lymphoma whose disease has unfortunately progressed, treating relapsed or refractory follicular lymphoma remains highly challenging, particularly in the third-line plus setting,” said Catherine Thieblemont, M.D., Ph.D., head of the hemato-oncology department, Paris University, Hôpital Saint-Louis Assistance-Publique-Hopitaux de Paris (APHP) in Paris. “The patients in this trial represent a historically difficult-to-treat patient population. The data presented today are especially notable because they demonstrated high overall and complete response rates for this investigational follicular lymphoma therapy and a preview for its potential as an alternative treatment option.”

Overall results from the pivotal cohort of 128 adult patients showed that : i. At a median follow-up of 17.4 months, the study’s primary endpoint ORR was 82 percent, which exceeded the protocol defined threshold for efficacy, with a CR rate of 63 percent, and 67 percent MRD negativity. ii. The median time to response was 1.4 months and median time to CR was 1.5 months. iii. Median progression-free survival (PFS) for patients who achieved a CR was not reached nor was the median duration of response, duration of CR, MRD negativity and overall survival. iv. An estimated 85 percent and 74 percent of patients who experienced a CR remained in response at 12 and 18 months, respectively.

Among prespecified subgroups, ORR and CR rates were generally consistent with the overall patient population. Notably, high-risk patients who were refractory to both anti-CD20 therapy and an alkylating agent achieved a 76 percent ORR and 56 percent CR; patients who were refractory to last prior treatment achieved a 74 percent ORR and 51 percent CR rate; and patients whose disease progressed within two years of first-line immunochemotherapy (POD24) achieved an 80 percent ORR and 61 percent CR.

Safety findings were consistent with previous epcoritamab trials, and epcoritamab was generally well tolerated. Following an optimized step-up dose regimen for FL patients (n=50) to reduce the risk and severity of CRS, 40 percent of patients experienced Grade 1 CRS and 8 percent experienced Grade 2 (no Grade 3 or higher CRS were reported) and no Immune Effector Cell-Associated Neurotoxicity Syndrome (ICANS) was reported. This data may support outpatient administration. Additional common treatment-emergent adverse events (TEAEs) from the pivotal cohort (greater than 20 percent) were injection-site reaction (57 percent), COVID-19 (40 percent), fatigue (30 percent), neutropenia (29 percent), diarrhea (27 percent) and pyrexia (25 percent). TEAEs leading to treatment discontinuation occurred in 19 percent of patients, and Grade 5 TEAEs occurred in 13 patients (10 percent).

“Follicular lymphoma patients who have experienced a relapse following heavy pre-treatment, or whose disease is not responding to available therapies, are considered high risk and are in need of alternative therapeutic options,” said Jan van de Winkel, Ph.D., Chief Executive Officer of Genmab. “The data presented at ASH reinforce what we have seen from our epcoritamab research and believe that this investigational bispecific antibody could potentially represent an important treatment option for patients living with relapsed or refractory follicular lymphoma. Along with our partner AbbVie, we look forward to progressing epcoritamab in clinical trials and discussing the results with regulatory authorities and remain committed to developing epcoritamab as a potential future core therapy for B-cell malignancies.”